Hydraulic jack



Feb. 10, 1953 D. JOHNSTON 2,627,722

HYDRAULIC JACK Filed Jan. 29, 1947 2 SHEETS- SHEET 1 Doz/6L H5 JOHNSTON,/Wwv gul,

Feb. 10, 1953 D. JOHNSTON 2,627,722

HYDRAULIC JACK Filed Jan. 29. 1947 2 sHEETs-SHEET 2 ,27 y Il 57M Il 6 2455 30 ,I 5y Il X 1 l l l l l 1 H y l,

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57 poum/a5 JOHNSTON) 27 39 0; 37 /0 28 VW M Patented Feb. l0, 1953UNITED STATES PAT ENT @FFE CE HYDRAULIC JACK Douglas Johnston,Huntsville, Ala'., assigner to General Fluid Machinery Company',Huntsville, Ala., a. corporation of Alabama.

Application January 29, 1947,'S'erialNo. 725,013

5 Claims. 1.

The present invention relates to a hydraulic jack.

It is an object of the invention to provide a hydraulic jack whereinleal@ in the hydraulic mechanism are largely prohibited and whereinthedesign is such that a solid steel'base may be used to reduce thelikelihood of leakage. A further object is to provide a particularlydesirable valve construction wherein there are brass inserts to form thevalve seats foreach of the` valves, and wherein all of the valvesY arelocated in a single opening and are accessible through this opening forreplacement. Another object is to provide inserts for the valvearrangement, including seat members and spacers thatminimize the numberof diiierent parts required.

A further object is to provide a jack of this' type wherein the ramAcan-be mounted in the center of the base and the valves disposed in asingle opening at one side of the base.

In the drawings: v

Fig. 1 is a plan view of the jack;

Fig. 2 is a vertical section on the line 2-2 of Fig. 1; v

Fig. 3 is a vertical sectional view taken on the line 3 3 of Fig. 1;

Fig. l is a horizontal section looking downwardly on the line 4;-4 ofFig. 3;v

Fig. 5 is an enlarged sectional view of the valve construction shown'inthelower part of Fig. 3;

Fig; 6 is a horizontal section through'the valve construction, taken onthe line 6-6 of Fig. 3; and

Fig. 7 is a front elevation of the jack, with the ram partly brokenaway.

The jack includes a base' lil that may be formed of steel in one solidpiece; This base Ie has a cut-out in its upper surface into which acylinder Il is threaded. A cap I2 is threaded into the upperend of thiscylinder, it having a hexagonal wrench fitting portion as shown inFig. 1. An oil reservoir tubing I3 fits between the cap I2 Yand the baseI and is sealed thereto to hold a-supply of `oil, as indicatedlinrFig.2.

The cylinder vI I lsli'dably receives ia piston head I towhich.a'tubularmember IGiis attached. This tubular'member is threaded toreceive a jack screw Il whichmay'be turned and thereby adjusted inandqout with respect tothe cylindrical portion I6. The screw has a head!I3' on it which may be disposed beneath the work to be lifted. The headI5, cylinder I6.' screw Il and head IS- constitute the ram of the jackand are centrally located on the base; Thefhead l5 has the usual sealingmeans onitsbottom'surface, so that hydraulic fluidforced"belowfthisvsealingfmeans 2t) will lift the ram. The cap I2, above the cylinder II,receives apacking ring' held in place by threaded` rings 2| screwedintothe cap I2 that compress the packing ring and maintain it in contactwith the cylinder It. As the head I is larger indiameter than thecylinder i6, the head will engage the lower ring 2|, at the upper end ofthe stroke, and loe'v prevented from` moving out of the base.

As'noted, the tubing I3 provides, with the cylinder I I, the base` Illand the cap I2, an annular oil reservoir 22. The'space within thecylinder l I and the base, below the'head I5, constitutes an operatingcylinder 23 for the jack.

Thel base is provided with an opening 21% that isdrilled thereint'o fromthe back part of the base. Aslopingcontinuation 25 of this openingM-leadsto the front of the'base and has varying diameters, as willappear.

The reservoir 22 has a passage 2l leading into the end 25 of theopening' 2t". It has another passage 28 that leads intojthe valveopening 212 towardV the other' end thereof. Between these two passages,there is a passage Ertl-lat leads into the operatingcylinder 23.

Upstanding from a middle part of the opening 24, there is a verticalport 3S thatopens into a pressure-cylinder 3 [threaded-into the topsurface of thebaseft'o onefside of the reservoir 22. This member 3'Ireceives an operating plunger 32 having 'a packing gland` cap 33attached to its end'.l The plunger rod 32 passes through the cap 33, andis' pivoted to a rocking lever 35. The rocking lever is, in turn,pivoted to a vertical lever 36 that is pivoted between brackets 3l onthe top' ofthe base. These pivot arrangements comprise'removable pinsheld in place bycotter pins, as shown. The lever 35 lhas asockettl' atits outer end. A pin do passes through the socket. Itv will be seenthat, when a handle, indicated at H, isrinsertedin the'socket, and thelever 35 is rocked up and down, the plunger will be moved up and'down.

The openin'g'll receives a series of valves, valve seat `inserts'andspacers. At the left end of the opening in Figs. 5 and 6, there is avalve seat insert 45. The opening2d is preferably cylindrical, and theinsert has an outside cylindrical surface'that slides'into the opening2li and substantially'seals therewith. The insert' has a valve lseatrecess wand an annular projection il at the-other end, with a'flui'dpassage 4B axially throughV the insert. A ball vali/e541 is 'engageablewith the' valve' seat.

There isa gasket" lfthatfiits'around the ex-l tension 41. To the rightof the gasket, there is a cylindrical spacer sleeve 52. This sleeve hasan inner, shouldered opening whereby it may receive a coil spring 53 anda ball Valve 54, and may conduct uid from end to end. It also has aplurality of lateral ports 55 at suitable points around Aits periphery.

Next to the right of the spacer, there is another valve seat elementthat is identical with the element 45. Then there is a gasket 56 andanother spacer 51 that is identical with the spacer 52.

There is a spring actuated ball check valve 58 that may be received inthe sleeve and which cooperates with the valve seat of another valveseat element 59.

Next, there is another gasket 68 followed .by two spacers, 6I and 62.The right end of the spacer 62 receives a washer' 53, against which asolid spacer 64 is engaged. This spacer 54 acts against a gasket 61identical with the gasket 5I. The assembly is held by a threaded plug 55that has a wrench receiving opening 65 therein. It may be seen that allof the spacers, gaskets, and valve seat elements are thus held inposition firmly When the plug 65 is tightened into place, and that theseveral gaskets are spread into sealing relationship with the walls ofthe opening 2 `4.

In the extension of the opening 24, there is a manually movable plunger68 that is threaded into a packing lgland fitting 69 that, in turn, isthreaded into an enlargement of the opening 25 of the base, and isadapted to compress packing 10. The plunger 68 has a head 1I that isreceived in an enlarged socket portion 12 of the opening 25. This head1I is shaped to be received in an internal opening in the end of thehandle H, that also engages within the sleeve 38 of the operating lever.The head has a cross pin 14 that is similar to the cross pin 40 in thesocket 38.

The disposition of the valve parts provides that the valve 50 Will beheld against its seat 46 in the seat member 45 by the plunger 68, whenthe plunger is turned down by rotation of the head 1 I. This preventscommunication from the port 21 that extends to the reservoir to theother parts of the opening.

The opening 28 leads through the ports 55 of the spacer 6I into theinterior of these spacers, and thence may ilow up against the ball valve58. The passage 29, that communicates into the pressure cylinder 23,connects into the spacer 52 and through the ports 55 thereof toestablish communication of the pressure cylinder with the space betweenthe two valves 50 and 54.

The interior of the operating cylinder 3l communicates through the port30 with the interior of the spacer 51 to the left of the valve 58 and tothe right of the valve 54. There are a sufficient number of ports 55around each spacer to insure communication from the several passages, asindicated.

At a desired elevation along the casing I3, there is a ller plug 16through which hydraulic liquid may be inserted. This plug establishes aproper liquid level.

Operation When it is desired to use this jack to lift some Work, thejack is disposed under the work with the jack screw I1 screwed outmanually to establish engagement or approximate engagement between thehead I8 and the work to be lifted. Thereupon, a suitable pipe handle H,with the necessary notch to engage over the pin 40, is inserted in thesocket 38. When the handle is lifted,

the plunger 32 is elevated, establishing a low pressure condition backof the valve 58. This causes the hydraulic fluid to be drawn through thepassage 28 from the reservoir 22, unseating the valve 58 in thisprocess, so that, when the plunger 32 reaches its top point, thecylinder 3| is properly charged with hydraulic fluid. Upon subsequentdepression 'of the hand lever and the plunger 32, the oil thus drawn inis forced outwardly from the cylinder 3l. The valve 58 then seats,checking the flow-back of this oil into the reservoir. The oil underpressure, however, unseats the valve 54 against its spring and passesout the ports 55 into the passage 29 of the cylinder 23, where it canact below the ram head I5. It thus causesthe head to be raised. When theplunger reaches the bottom of its stroke, the pressure thus applied isrelieved and the valve 54 reseats, checking the outflow of such oil.Thereupon, the cycle is repeated `until the work is elevated as far asdesired.

When it is desired to lower the jack, the handle is removed from thesocket 38 and is inserted over the head 'II of the plunger 58. It isturned to unscrew the plunger and withdraw it from the valve 50 whichhas been maintained on its seat by the plunger 68. The pressure of theram downwardly on the hydraulic duid in the cylinder 23 causes thisiluid then to iiow past the valve 50 into the passage 21 and back intothe reservoir, so that the jack is lowered.

In servicing the jack, the principal members subject to wear are readilyaccessible. When it is desired to remove the ram, the threaded members2| and the packing ring are withdrawn. Then the ram may be pulled out,and, if it is necessary to replace the washer 20, the same may bereadily done by removing its retaining screw as indicated by thedrawing. Thereupon these parts may be conveniently replaced.

In similar fashion, the operating plunger 32 may be removed, as theseveral levers are held together by cotter pins. When the pins areremoved, the gland nut 33 may be unscrewed and the plunger drawn outthrough the packing and its parts repaired. If need be, the wholecylinder 3I may be unscrewed and repaired or replaced.

The valve yarrangement provides for very easy service with a minimumnumber of different types of repair parts. This comes about because, inthe rst place, all of the valves are immediately :accessible when theplug lE55 is withdrawn. Also, the valve seat inserts 4and spacer sleevesare all duplicates, so that only two types of such parts are required.The gaskets 5I are conventional. All of the ball valves are identical.The pressure relieving means, consisting of the plunger E8 andassociated p-arts, are self-compensating for all normal Wear because ofthe threaded arrangement.

What is claimed is:

l. In a jack, a base, a hydraulic fluid reservoir, an operatingcylinder, a ram in the operating cylinder, a pressure cylinder, apressure producing means in the pressure cylinder, :an elongated,cylindrical opening of constant cross section extending at leastpartially through the base and having van entrance at one surface of thebase, a first passage from the opening to the reservoir, a secondpassage from the opening to the pressure cylinder, -a third passage fromthe opening to the operating cylinder, a fourthpassage from the openingto the reservoir, removable Valve means in the opening between theirstand second passages. removable valve means in the opening between thesecond and third passages, and removable valve means in the openingbetween the third and fourth passages.

2. In a jack, la base, a hydraulic uid reservoir, an operating cylinder,a ram in the operating cylinder, a pressure cylinder, a pressureproducing means in the pressure cylinder, an opening in the base havingan entrance at one surface of the base, :a rst passage from the openingto the reservoir, a second passage from the opening to the pressurecylinder, a third passage from the opening to the operating cylinder, afourth passage from the opening to the reservoir, valve means in theopening between the rst and second passages, valve means in the openingbetween the second and third passages, and valve means in the openingbetween the third and fourth passages, said valve means being disposedlongitudinally within the opening in yabutting relationship.

3. In a jack, a base bounded by a plurality of intersecting surfaces, ahydraulic fluid reservoir, an operating cylinder, a ram in the operatingcylinder, a pressure cylinder, a pressure producing means in thepressure cylinder, an opening extending at least partially through thebase and having one end thereof terminating lat a surface so as toprovide an entrance into the opening, a rst passage from the opening tothe reservoir terminating at la surface of the base so as to provide anentrance into the first passageway, a second passage from the opening tothe pressure cylinder, a third passage from the opening to the operatingcylinder terminating at a surface of the base so as to provide anentrance into the third passageway, a fourth passage from the opening tothe reservoir terminating at a surface of the base so -as to provide anentrance into the fourth passageway, a fth passage from the opening to asurface of the base, valve means in the opening between the first andsecond passages, valve means in the opening between the second and thirdpassages, valve means in the opening between the third and fourthpassages, manually operative valve actuating means in the fifth passage,and means closing the entrances of the opening and the passages.

4. In a jack, a base bounded by :a plurality ofv intersecting surfaces,a hydraulic iluid reservoir,

an operating cylinder, a ram in the operating cylinder, a pressurecylinder, a pressure producing means in the pressure cylinder, astraight opening extending at least partially through the base andhaving an entrance at one surface of the base, three separate lateralpassages connecting the opening with the reservoir, the pressurecylinder and the operating cylinder, respectively, and substantiallyidentical valve means disposed in the opening in labutting relationshipso as to control the flow between adjacent lateral passages, each ofsaid valve means including a valve seat, a valve element cooperable withthe valve se-at, and a spacer, the valve seats being interchangeable,the valve elements being interchangeable, -and the spacers beinginterchangeable.

5. In a jack, a base bounded by a plurality of intersecting surfaces, ahydraulic iiuid reservoir, an operating cylinder, a ram in the operatingcylinder, a pressure cylinder, a pressure producing means in thepressure cylinder, a straight opening extending at least partiallythrough the base and having an entrance at one surface of the base, fourseparate lateral passages connecting the opening with the reservoir, thepressure cylinder, the operating cylinder, and the reservoir,respectively, and substantially identical valve means comprising a valveseat, a valveV element cooperable with the valve seat. and a spacerdisposed in the opening so as to control the :dow between adjacentlateral passages.

DOUGLAS JOHNSTON.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,011,213 Lemp Dec. 12, 19111,388,602 Rotteleur Aug. 23, 1921 2,032,309 Rechard et al. Feb. 25, 19362,042,727 Mueller June 2, 1936 2,306,012 Campbell Dec. 22, 19422,393,405 Page Jan. 22, 1946 2,412,414 Mueller Dec. 10, 1946 2,439,796Dearsley Apr. 20, 1948 2,447,650 Haumerson Aug. 24, 1948

